Best MacOS 4K Monitor Size - 27", 28" or 32"

[hungryghosty]

I'm planning on buying a new 4K monitor to use with my Macbook Air and Windows Desktop PC. I'm trying to decide what size of monitor to purchase?

Any suggestions what size is best for image/text clarity. I'd likely be looking to run it at a scaled resolution (looks like ~1440p) as 4K native will be too small at 27-32".

For that purpose what monitor size would be best (27", 28" or 32")?

 

[PaulD-UK]

Apple has traditionally used the same visible pixel density across all desktop monitors, so if you have multiple monitors, windows don't change in size as you drag them from screen to screen.
This 218ppi means that for 1440p screens, like pre-2014 iMacs and the Thunderbolt Display, you had a 27" screen, Ana an apparent density of 109ppi - the same as the old 1440 Apple screens.

5K iMacs were 'retina' HiDPI 1440p with 5280x2880 pixel screens.

The XDR Pro Display was introduced, still 218ppi, so to be 6K it had to have a 32" screen.

A 4K screen, like the retina 21.5" iMac, still ~218ppi, has a 21.5" screen, and the 24" iMac is 4.5K.

So your proposed larger screen 4K monitor isn't going to have the Apple pin-sharp HiDPI performance that comes with Apple screens, when viewed at 1440p.

You take your pick as to which way you want to deviate from Apple's way of doing things.
A bigger screen further away from your eyes will give you acceptable sharpness, but bigger actual text/window size.
If you want to work closer to your monitor, then 27" will match Apple's text/windows size, but will not be as sharp as a 5K iMac was.

 

[hungryghosty]

Apple has traditionally used the same visible pixel density across all desktop monitors, so if you have multiple monitors, windows don't change in size as you drag them from screen to screen.

So your proposed larger screen 4K monitor isn't going to have the Apple pin-sharp HiDPI performance that comes with Apple screens, when viewed at 1440p.

I appreciate that it’s a compromise buying a 4k display however I need a monitor that works on both MacOS and Windows so I can’t purchase a monitor that only works with my Mac like the Apple studio display.

From talking to people on here most seem to feel that a 4k monitor scaled looks better in MacOS than a 27-32” 1440p display at native resolution? Would you agree with that sentiment?

In that context would a 28” or a 32” 4k display look better in MacOS? Or should I stick with a 27”/34” ultrawide 1440p monitor at native resolution?

 

[Fishrrman]

Depends on
- your eyes
and
- what resolution you want.

27" 4k (running at "looks like 1080p") works for me.

What I'd really like is 32" 5k (running at looks like 1440p), but no one makes a panel in that size/resolution combination).

 

[hungryghosty]

Depends on
- your eyes
and
- what resolution you want.

27" 4k (running at "looks like 1080p") works for me.

What I'd really like is 32" 5k (running at looks like 1440p), but no one makes a panel in that size/resolution combination).

Does the 4K 27" monitor look bad at "looks like 1440p" or do you just prefer the size of the text/etc at "looks like 1080p"?

 

[Fishrrman]

"Does the 4K 27" monitor look bad at "looks like 1440p" or do you just prefer the size of the text/etc at "looks like 1080p"?"

"Looks like 1440p" on a 27" display -- text is too small for my old eyes.

For this reason, the 5k iMac didn't appeal to me, as I wouldn't have used it at "retina resolution" (looks like 1440p).

I'm typing this on a MacBook Pro 14", and I don't even use this at "factory" resolution.
I use "one step larger"...

 

[gilby101]

Any suggestions what size is best for image/text clarity.

With a 4K monitor you will get best text clarity with 21.5" (but not looks like 1440p). It will steadily get worse as you go up in size.

You have to try different monitors - take your MBA to a shop and try them as none of the ones you suggest can be called best. A vote is not what you need.

 

[hungryghosty]

With a 4K monitor you will get best text clarity with 21.5" (but not looks like 1440p). It will steadily get worse as you go up in size.

You have to try different monitors - take your MBA to a shop and try them as none of the ones you suggest can be called best. A vote is not what you need.

That’s going to be a challenge as I don’t have any stores near me with a selection of computer monitors to try unfortunately so might be a case of having to order one based on feedback from this forum?

 

[Fishrrman]

27" with 4k resolution will be fine.
You'll just have to trust me on this.

Brand?
Dell
Samsung
LG
Viewsonic
Phillips
etc.

(go to amazon and check user reviews. PAY ATTENTION to the negative reviews as well as the favorable ones. To what issues were some folks objecting?)

 

[hungryghosty]

27" with 4k resolution will be fine.
You'll just have to trust me on this.

Brand?
Dell
Samsung
LG
Viewsonic
Phillips
etc.

(go to amazon and check user reviews. PAY ATTENTION to the negative reviews as well as the favorable ones. To what issues were some folks objecting?)

I guess the main issue some folk object to is the need to run a 27”+ 4k monitor at a scaled resolution and the text clarity not being sharp in MacOS as a result

 

[Fishrrman]

"I guess the main issue some folk object to is the need to run a 27”+ 4k monitor at a scaled resolution and the text clarity not being sharp in MacOS as a result"

Set the 4k display to "looks like 1080p".
Text will be scaled perfectly (as clear as it gets) and it won't put any "load" on the graphics processing.

If I'm not mistaken, this is the "default resolution" that the OS will choose when it detects a 4k display...

 

[hungryghosty]

"I guess the main issue some folk object to is the need to run a 27”+ 4k monitor at a scaled resolution and the text clarity not being sharp in MacOS as a result"

Set the 4k display to "looks like 1080p".
Text will be scaled perfectly (as clear as it gets) and it won't put any "load" on the graphics processing.

If I'm not mistaken, this is the "default resolution" that the OS will choose when it detects a 4k display...

That's the issue though in that a 27/28" 4K monitor running at "looks like 1080p" will be perfectly sharp but the text, fonts and other screen aspects will look quite large as you're running at the scale you'd normally have on a 1080p 24" monitor. On a 32" 4K monitor this would be even worse hence the need to run at “looks like 1440p”

 

[MikeDr206]

I have a 6k display (the Dell) running at the preferred ”looks like” resolution, and sadly with my aging eyes thinking of changing it to “looks like” 2560x1440.

 

[hungryghosty]

Has anyone tried MacOS on one of the new OLED 27" 4K monitors that have just recently released?

The 5 Best OLED Monitors - Spring 2025

If you're looking for the best OLED gaming monitor and need the highest refresh rate possible, there are some 480Hz gaming OLEDs, like the Sony INZONE M10S.

www.rtings.com

Contemplating buying one to use with my Mac and PC.

 

[motrek]

I guess the main issue some folk object to is the need to run a 27”+ 4k monitor at a scaled resolution and the text clarity not being sharp in MacOS as a result

There's hardly any difference between text being rendered at a bigger size and then scaled down vs. text being rendered at that same size natively.

In other words, the fact that it's a scaled resolution makes very little difference to anything.

Text looks less sharp on a 4K monitor vs. a 5K monitor because the former has 44% fewer pixels. Not really a big mystery.

 

[AlphaCentauri]

There's hardly any difference between text being rendered at a bigger size and then scaled down vs. text being rendered at that same size natively.

In other words, the fact that it's a scaled resolution makes very little difference to anything.

Text looks less sharp on a 4K monitor vs. a 5K monitor because the former has 44% fewer pixels. Not really a big mystery.

Scaled resolutions always look better than native resolutions on MacOS, due to the way it renders text (no subpixel antialiasing).

However, using a fractional scaling results in less sharp image than using integer scaling. So if one can stand (or needs) GUI elements being bigger on 4K monitor in „looks like 1080p” mode, this will result in the best text clarity.

 

[motrek]

...
However, using a fractional scaling results in less sharp image than using integer scaling. So if one can stand (or needs) GUI elements being bigger on 4K monitor in „looks like 1080p” mode, this will result in the best text clarity.

Or, "looks like 1080p" looks a lot more clear than "looks like 1440p" because everything is 33% bigger by default and big things look more clear.

I took a screen shot of the first line of your post. Then I increased the font size by 33% and scaled the resulting image back down by 33% to simulate what the same size text would look like with fractional scaling.

If there's a useful difference between the clarity of these two lines, I'm not seeing it.

 

[AlphaCentauri]

There’s no such thing as half pixel, hence the difference in rendering quality between non-integer and integer resolution.

With 4K, the actual resolution is always 3840x2160. If the screen is rendered as 1080p, both horizontal and vertical resolution is divided by 2, hence sharp text and edges. With 1440p, on the same screen, the scaling factor is 1.5. There’s no way to display half pixels, hence slightly fuzzy text edges and fuzzy GUI elements. There’s no way around it.

Whether someone can see it or not, it’s a different matter. Me and many others do. Nothing precludes you from using fractional scaling - I’m just pointing out that the text quality is better with integer scaling.

 

[motrek]

There’s no such thing as half pixel, hence the difference in rendering between non-integer and integer resolution.

With 4K, the actual resolution is always 3840x2160. If the screen is rendered as 1080p, both horizontal and vertical resolution is divided by 2, hence sharp text and edges. With 1440p, on the same screen, the scaling factor is 1.5. There’s no way to display half pixel, hence slightly fuzzy text edges and fuzzy GUI elements. There’s no way around it.
...

You're working off of the assumption that, at native resolution (or an integer-scaled resolution), edges of things are displayed on pixel boundaries.

Take a screen shot of MacOS sometime, zoom way in, and check it out. Precious little is displayed on pixel boundaries.

 

[AlphaCentauri]

You're working off of the assumption that, at native resolution (or an integer-scaled resolution), edges of things are displayed on pixel boundaries.

Take a screen shot of MacOS sometime, zoom way in, and check it out. Precious little is displayed on pixel boundaries.

You are disputing math, not my point of view 🤣

Please tell me how any computer can display half pixel on a screen with finite number of pixels WITHOUT INTRODUCING ARTIFACTS.

Millions of people is using fractional scaling everyday and it’s absolutely no problem for most. But to say that integer scaling and fractional scaling result in the same image quality is factually incorrect.

 

[motrek]

You are disputing math, not my point of view 🤣

Please tell me how any computer can display half pixel on a screen with finite number of pixels WITHOUT INTRODUCING ARTIFACTS.

Of course you're absolutely right, if the computer is trying to display e.g. a vertical black line on a white background on a pixel boundary, then all the pixels are going to be either black or white, if you're at native resolution (or an integer-scaled resolution).

And if you display the same line with fractional scaling, you're going to get a "fuzzy" grey line at the boundary of black and white.

So, sure.

But that's only relevant if the computer displays a lot of lines that are on a lot of pixel boundaries.

For any content that ISN'T on pixel boundaries, none of this matters. There are already fuzzy grey pixels, it's not going to matter if you scale the image and it produces different fuzzy grey pixels.

And if you're looking at MacOS, there are precious few things that are rendered on pixel boundaries, i.e., there are very few instances where what you're talking about could possibly matter. Certainly not for any text or images, which is almost everything on the screen.

 

[AlphaCentauri]

That’s why fractional scaling is being used. Those artifacts are of negligible importance to most. I’m not disputing this.

I’m only contesting that there’s no difference in image quality between integer and fractional scaling, that’s all.

 

[motrek]

That’s why fractional scaling is being used. Those artifacts are of negligible quality to most. I’m not disputing this.

I’m only contesting that there’s no difference in image quality between integer and fractional scaling, that’s all.

Sure, there's a difference. It's a small difference. Whether or not it's noticeable is debatable, and that's a debate I'd rather not have.

But what I'm tired of is people blaming fractional scaling for reduced sharpness when the VAST MAJORITY of the difference is easily explained by something else.

"4K isn't as sharp as 5K because of fractional scaling." Really? How about, 4K isn't as sharp as 5K BECAUSE IT ONLY HAS HALF AS MANY PIXELS.

It's sort of like arguing that a 6 megapixel photograph is not as sharp as a 12 megapixel photograph because of the way the Bayer filtering is being done. No. IT HAS HALF AS MANY PIXELS.

"1080p is more clear than 1440p because it doesn't do fractional scaling." Really? How about, it's more clear because EVERYTHING IS 33% BIGGER.

Fractional scaling gets a bad rap on these forums and it's 99% undeserved.

 

[AlphaCentauri]

You are right about 4K monitor vs 5K monitor. But on the same monitor (be it 4K or 5K), integer scaling always wins in regards of image quality.

Let’s take Apple ASD at 5K: do you claim that “looks like 1440p” is less clear than “looks like 1080p”, because “everything is 33% bigger at 1080p”?

 

[motrek]

You are right about 4K monitor vs 5K monitor. But on the same monitor (be it 4K or 5K), integer scaling always wins in regards of image quality.

Let’s take Apple ASD at 5K: do you claim that “looks like 1440p” is less clear than “looks like 1080p”, because “everything is 33% bigger at 1080p”?

That's not a legitimate comparison, because internally, MacOS is rendering everything at twice the "looks like" resolution and then scaling to match the physical resolution.

So if you've set your display to "looks like 1080p" then everything is being rendered at 3840x2160. Then you're talking about displaying it on a 5K display that has a physical resolution 5120x2880.

In other words, you're taking an 8.3 megapixel image and displaying it on a 14.7 megapixel display. Obviously it's not going to be very sharp.

Now, if you could get MacOS to render everything internally at 4x the "looks like" resolution, we could have a debate.